95 xlt needle, seats, Jets

DCJ · Mar 9, 2012

Hello, Could use any suggestion here. This is my first attempt at working on these carbs. I need to replace the needle&seat and the jet .
I read that I should get the needle with the vitron tips, but looking in the dennis kirk catalog, it isnt abliable. Is this the right on to get(without the viton. Or is the another place to go besides dealer.
Also I read that I may want to get the main jets 1 or to 2 sizes larger, as the factory ones made the xlt run to rich.
Last, was would be the right jetting for 2000- 5000 feet?
I know I have a bit to learn, but any suggestions would be great.
Thanks

bolty16 · Mar 9, 2012

The XLT's are know for running hot (lean) I would fatten it up maybe one jet size and probably 2 or 3 if it is piped or anything like that. I have pipes and I am running 3 up from stock to keep it a little more rich. then found that moving my E clip on jet needle down 1 spot is good to then a little tweak on the idle screw. I have learned by guess and check. But remember high alt is thin so go fat and low alt is fat so lean it out just a tad. But from 2k-5k you will use the same setup, just get ready for some on the trail tweaking.

retiredpop · Mar 9, 2012

Some general info:

As the jet number goes up it flows more fuel so machine will run richer.

Altitude and temperature affect what jets you need. As altitude goes up you need smaller jets. Similarly as it goes down you need bigger jets.

As temperature goes up you need smaller jets and vice versa. So as you can see it is a balancing act between temperature and altitude.

In your case where you don't have a lot of change in altitude you just have to mainly be concerned with temperature.

Generally you want to jet for the coldest days you will ride in during the winter and then in spring you might want to lean it down a bit as temperatures warm up.

I looked up a jetting chart for an XLT base model. Jets are recommended as follows:
For 0 to 3000 feet;
temp of -20F and below = 230 main jets
-20F to +10F mains = 220
+10F to +40F mains = 210
above +40F mains = 200

For 3000 to 6000 feet which is where you will jet
-20F and below mains = 210
-20F to +10F mains = 200
+10F to +40F mains = 190
+40F and above mains = 180

In our experience with our 95 XLT SKS which had the same carbs as yours we ran about 2 jet sizes leaner than manufacturers recommendations when it was stock. They usually err on the rich side to avoid warranty work. I feel if you run recommended jetting you should not have to worry about being too lean especially if you are stock. Once you do some reading and learning about reading spark plugs you may want to fine tune your jetting.

retiredpop · Mar 9, 2012

bolty16 said:
But remember high alt is thin so go fat and low alt is fat so lean it out just a tad.

You wrote it backwards my friend.

bolty16 · Mar 9, 2012

I did, great catch.

Age and experience has served you well.

DanB · Mar 9, 2012

Definitely use the viton needles.

The place to go for Mikuni carb parts is Sudco. Here's a link to a page where you can access their catalog (I recommend the down-loadable PDF).

http://www.sudco.com/onlinecat.html

DCJ · Mar 9, 2012

Thanks for the replys,
as of last week i could only did it started when cold with starting fluid in the cylinders. Then road last sunday, got 3 miles and just died. Wouldnt start when warm, wouldnt start on starting fluid either.
I have good spark, so i'm sure its a fuel thing. Have rebulit/cvlean card, but did not replace anything. I think thats the next step. Also check the tank, fule lines and pump.

retiredpop · Mar 10, 2012

Here is a fairly good video to watch.

http://www.youtube.com/watch?v=AOJlHIUUBk0&feature=player_embedded#!

rupp76 · Mar 12, 2012

where did you find the charts for the jetting and altitudes and what not? i have an 83 triple 600, thats piped and it runs great but is doggy between 4000-5000 rpms, then it runs strong, but when pegged out it starts to come off the power band like its ran out of power? any suggestions, we ride between 4000-6000 feet

retiredpop · Mar 12, 2012

I used to own a 95 XLT so still had some info on it. On your 83 I wonder if it could be the fuel pump. I had an old Blizzard that would start to run like that at full throttle after a while and it turned out to be a weak fuel pump. It just couldn't keep the float bowls filled when it ran at WOT for a bit. Doggy at the bottom end could be clutch belt deflection or possible air screw adjustment on carbs.

rupp76 · Mar 13, 2012

yeah i have dropped the needles as far as they will go, and it helped tremendously, but your right about that oump ill check that, my olp rupp did that once before too, i may need to re jet it for our altitude...its just a trail sled and night ride machine, its a my backups back up so ite not at the top of the chain lol thanks]

mike_s · Mar 13, 2012

I would try very very hard to never use ether (starting fluid) on a snowmobile engine. They are simply not strong enough to handle the posible combustion pressures and the possibility of it igniting in the case is too high. That could end in a big mess.

DCJ · Mar 13, 2012

Ok, Im'm want to see if these are the right parts to get. I took apart a carb and heres what I found. (it's a 95 xlt with the vm34 carbs, everything stock)
1.main jet was a 185, want to go 190 ?
2.pilot jet is a 35 want to stay at 35?
3.needle and seat already had a viton needle. can these wear out too? Figure just replace with new needle/seat with viton tip(786-15005 mikuni #)?
4. Now here my confusion, Mukuni charts show that the vm34 carb use a 159 series for the needle jet. The one in my carb has a 166 (166 Q2 stamped) series needle jet, which look like it goes with the vm38 carbs. Are these needle jets interchangeable? Or could this be a cause of my hard starting, low power?
5 the needle is stamped 6dp17.
6. Will get new bowl gasket
I'm now not sure what needle jet and needle to order.
Any suggetion as to the correct part to get? Any help is greatly apprectiated.

retiredpop · Mar 14, 2012

185 main jet should be just about right on. I would leave it.

The 35 pilot jets were stock so should be good. Ensure they are totally clean including all the small holes on the sides of the jet. They tend to plug with varnish and cause some low end troubles.

The needle jet should be the Q2(166) with a 6DP17 jet needle with the clip in position 3. While they are physically interchangeable you don't want to start changing needle jets as that will totally throw your jetting out the window. The 159 flows less fuel than the 166 so you would have no idea where to even start with mains, and jet needles.

Air screw should be 1 turn out for initial setup. To fine tune it turn them all one way or another 1/8 turn at a time to get the best combination of smooth idle and quick low end throttle response when you snap open the throttle from idle.

ttyR2 · Mar 25, 2012

If I recall, the Mik's on the XLT use a special float valve assembly and Sudco doesn't have them. The other jet parts should be available through Sudco though.

Search

95 xlt needle, seats, Jets

DCJ

Free Member

bolty16

Free Member

retiredpop

Well-known member

retiredpop

Well-known member

bolty16

Free Member

DanB

Member

DCJ

Free Member

retiredpop

Well-known member

rupp76

Free Member

retiredpop

Well-known member

rupp76

Free Member

mike_s

Well-known member

DCJ

Free Member

retiredpop

Well-known member

ttyR2

New member

Similar threads